1. Field
The present disclosure relates generally to heating parts and, in particular, to heating composite parts. Still more particularly, the present disclosure relates to a method and apparatus for dynamically controlling the heating of a composite part during heating of the part.
2. Background
Fabrication of a part may sometimes include curing the part. The curing of a part may be performed by applying heat, pressure, or both to the part. As one example, a part may be placed on or within a tool and then heated using an oven. In another example, the part may be placed on or within a tool and then heated and pressurized using an autoclave.
Variations in the geometry of a part may affect heat transfer rates during curing of the part. For example, curing parts that have non-uniform shapes may be more difficult than desired when using an autoclave, pressure chamber, oven, or other type of heating system. A part that does not have homogenous cross-sections may be considered as having a non-uniform shape. As one specific example, a non-uniform part may have a cross-sectional shape and configuration that varies along an axis that extends from one end of the part to the other end of the part. This type of cross-sectional shape and configuration of the part and tool may cause variations in the amount of heat energy required to change the temperature of the part and tool.
For example, when curing a part within an autoclave, airflow inside the autoclave may have different speeds relative to different locations on the part, depending on the shape and size of the part. These different airflow speeds may cause different rates of heat transfer from the air inside the autoclave to the part. The portions of the part that heat faster may reach a maximum cure temperature for the part faster than the portions of the part that heat slower.
As one specific example, when a horizontal stabilizer for an aircraft is cured in an autoclave, airflow may be faster over the outer surface of the horizontal stabilizer as compared to the airflow around the integral stiffeners that form channels within the horizontal stabilizer. Consequently, the stiffeners may cure at a rate that is slower than the outer surface of the part. Further, meeting cure requirements with respect to temperature and cure rate may be more difficult than desired. Therefore, it would be desirable to have a method and apparatus that take into account at least some of the issues discussed above, as well as other possible issues.